Abstract Adverse patient safety event rates remain stubbornly high in hospitals. For children, adverse events are 1.5-2 times more common than in adult inpatients (40.0 vs. 25.1 harms/100 admissions). This proposal uses an untapped source of safety event reporting?patients and family members of hospitalized pediatric patients?to address knowledge gaps identified by the NICHD: the epidemiology of pediatric safety events; strengths and limitations of current methods of error reporting systems; methods to prevent pediatric medication errors; and the development of learning health systems to address inpatient pediatric safety. Text messaging and mobile phone applications technologies offer the opportunity to gather patients' and families' safety reports in real-time and anonymously, addressing limitations of prior work. Our mobile phone-based approach, Family Input for Quality and Safety (FIQS), was developed in partnership with families and clinicians, and was pilot-tested on a pediatric medical-surgical unit, with enthusiastic engagement from participants and staff. The objectives of this proposal are to address the rigor of prior work in the following aims, while testing the approach in other hospital units (e.g., ICU, hematology-oncology) and in a safety net hospital. Aim 1: Describe variations in safety events across care settings and populations using family- and patient-generated safety reports (N~6,500 participants; N~3000 FIQS Reports). This will use the real-time mobile phone tool to determine differences in family and patient safety reports by hospital setting, medical complexity, language, health technology literacy, and patient and family-member demographics. Aim 2: Compare FIQS reports to clinician-generated safety reports documented in incident reports and in the medical record. This will employ mixed-methods, quantifying the number of overlapping and unique events from each source, and using qualitative analysis to describe unique domains covered in each source. Aim 3: Evaluate an improvement collaborative focused on incorporating family and patient reports issues into safety efforts. The collaborative will include all participating units; domains of focus will be medication and communication. Mixed-methods will be used to evaluate the collaborative using the theory-driven RE-AIM implementation science framework. The proposed research is innovative in its paradigm-shifting conceptual model of 1) patient-engaged quality improvement, 2) its use of mobile phone technologies to gather real time data, and 3) its use of an improvement collaborative to develop robust implementation strategies for incorporating family and patient reports into safety efforts. The contribution of the proposed research will be a description of family and patient safety reports across multiple types of inpatient settings in two diverse health systems; a comparison of family and patient safety reports to other methods of detecting adverse events; and cross-setting implementation tools and strategies to incorporate family and patient safety reports into care. These contributions will be significant because they are key steps in implementing and evaluating a potential new approach to improving pediatric inpatient safety.